Work on this grant involves the following areas: Calcium ion regulation of gastric secretory activity, human gastrin response to secretin post vagotomy, effects of cation and pH on acid and gastrin output, truncal vagotomy and the antral "G-cells", an improved stroma-free hemoglobin solution. BIBLIOGRAPHIC REFERENCES: Greenburg, A.G., Pearl, J., Belsha, J. and Peskin, G.W.: An Improved Stroma-Free Hemoglobin Solution. Surgical Forum, 26:53, 1975. Saik, R.P., Greenburg, A.G. and Peskin, G.W.: The Spectrum of Cholangitis. Amer. J. Surgery, 130:143, 1975.